The two beams can be used simultaneously to achieve spectral coverage over the full spectral range of 320 nm to 1.7 microns. Each beam supports long-slit and multi-object spectroscopy, Fabry-Perot imaging spectroscopy, and spectropolarimetry. The visible beam supports high-speed spectroscopic modes as well.

With simultaneous spectral coverage from the UV (25% throughput at 320 nm) out to 1.7 microns in the IR, the RSS is unique among or superior to existing 8-10m telescopes in the UV, in medium resolution spectroscopy, in Fabry-Perot spectroscopy, and in spectropolarimetry.